Anyone else experience their ninjas valves never moving since the initial inspection? My initial inspection was at 12k with every valve needing the next size shim then 20k, 30k and now 40k with no adjustments needed. I'm not complaining, it just seems to good to be true. And you guys know I ride my **** hard from time to time so it's not like I'm babying it.

The other thing I noticed was my spark plug electrodes are going away. I'm not even going to try re-gapping since it seems like it has been eaten away at the last 2mm only. Its hard to see but you can just make out the tip is thinner at the end. These are NGK CR8EIX IRIDIUM PLUGS so they are supposed to last longer then stock. They were installed at 12k miles so is 28k good for these plugs or should I have seen a longer life?
http://i1157.photobucket.com/albums/p596/rojoracing53/Mobile%20Uploads/F9F10120-2CF1-4D2F-941C-276CE134BDED_zpsrdypgjws.jpg
http://i1157.photobucket.com/albums/p596/rojoracing53/Mobile%20Uploads/D57CF973-3AB4-42F9-8199-10D7F2E1FD1A_zps9qemvwuo.jpg

Please see this:

http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqread.asp?mode=nml

Little wear of valves and seats is possible with proper cooling of the seats and good oils.

Well aside from the wear on the tip I think my plugs look perfect, I know these things are supposed to wear out but I've never knew what exactly wears out on them and how long it actually takes. On the race bikes we replace them every season just because you basically get new bikes every year and on the dirt bikes you foul plugs before they ever get a chance to wear out.

The two picture that note erosion say its cuased from lead in the fuel but I'm pretty sure Ca hasnt use lead in pump gas since the 80's-90's:confused:


I'm ok with new plugs every 20-30 miles with the hard riding and high reving I do, I was just wondering if it was normal.

.... These are NGK CR8EIX IRIDIUM PLUGS so they are supposed to last longer then stock. They were installed at 12k miles so is 28k good for these plugs or should I have seen a longer life?


NGK doesn't even have an concrete answer about longevity. Even though they say the plugs are designed to last 40-50k miles (http://www.ngksparkplugs.com/pdf/DYK_LaserIridium_vs_Iridium%20IX.pdf)(These numbers are probably typical for an automobile), I don't think they had an engine whose rpm speed and spark rate is 2-3 X's that of the average engine in mind (thus making for a shorter life span). They also refer back to the manufacturers recommendations. Seeing that you've exceeded Kawasaki's recommendation by 9k miles, I would guess you got double the life of a normal plug under the circumstances.

I am sure the arcing wears the tips away, also if in a car these last 75-100k miles then a bike revving at at least twice the rpms and therefore twice the electric arcing, will wear them out 2x quicker.
As to the valves, my guess is they work harden as they bang into the seats and therefore the biggest difference is in the beginning since they are the softest.

NGK doesn't even have an concrete answer about longevity. Even though they say the plugs are designed to last 40-50k miles (http://www.ngksparkplugs.com/pdf/DYK_LaserIridium_vs_Iridium%20IX.pdf), I don't think they had an engine whose rpm speed and spark rate is twice that of the average engine in mind. They also refer back to the manufacturers recommendations. Seeing that you've exceeded kawasaki's recommendation by 9k miles, I would guess you got double the life of a normal plug under the circumstances.

Lol I didn't even know the recommended replacement intervals for the stock plugs or the fact that I over shot it by so much. This makes me feel good about the 28k I got out of these as well as the wear I'm seeing. In case any one cares Kawi calls for .030-.040 on the gap and I've eroded to .043. My bike over the last 6k miles runs a little finicky when its cold. I still don't need to use the choke but it definitely is starting to get closer to the point where it could benefit from a like choke on first startup. I was hoping my valves were causing this cold blooded syndrome but maybe it's the plugs. I guess after I get the new plugs in and re-sync the carbs I'll see how well it fires up the next time.

........The two picture that note erosion say its cuased from lead in the fuel but I'm pretty sure Ca hasnt use lead in pump gas since the 80's-90's:confused:


You are right, there is no lead in gasoline nowadays.

Is your ignition system stock or modified?

Anyone else experience their ninjas valves never moving since the initial inspection? My initial inspection was at 12k with every valve needing the next size shim then 20k, 30k and now 40k with no adjustments needed. I'm not complaining, it just seems to good to be true. And you guys know I ride my **** hard from time to time so it's not like I'm babying it.


You can probably chalk it up to bigger, longer, stronger, cleaner, and more complete combustion, with less carbon deposits to interfere with valve seats. Like Motofool said, "Little wear of valves and seats is possible with proper cooling of the seats and good oils. " Apparently your plugs have done just that and pulled the heat away from the combustion chamber like they are designed to.

Aside from a stage 2 Dynojet kit and full Leo exhuast my bike is stock motor wise. I am pretty good about changing the oil every 3k miles and sooner around trackdays, and I always use motul 300v factory line oil. I want this thing to last me a 100k miles and it seems I may be on the right path so far.

I want this thing to last me a 100k miles and it seems I may be on the right path so far.

Just watch out for camrys